Locking open end wrench with lock retaining means



Sept- 1958 J.IE. SWANSTROM ETAL 2,849,908

LOCKING QPEN END WRENCH WITH LOCK RETAINING MEANS Filed Aug. 6, 1957 MM VW 7 4770 4:26

LOCKING OPEN END WRENCH WITH LOCK RETAINING MEANS Application August 6, 1957, Serial No. 676,532

7 Claims. (Cl. 81-165) This invention relates to wrenches. More particularly it relates to adjustable open end wrenches having locking means associated therewith.

It is a common problem with wrenches having relatively adjustable jaws that the jaws have a tendency dur ing use to shift to a smaller or larger size as a result of jarring, bumping, etc. Some wrenches have been designed to provide locking means for preventing such shifting of the movable jaw during use. An example is the open end wrench disclosed in U. S. Letters Patent No. 2,719,449. Such wrenches, however, have all had certain disadvantages in that they are either difficult and unhandy to lock and unlock, or are too cumbersome in construction, or require two hands to lock and unlock, or are unsound mechanically as evidenced by the fact that they become or are initially loose fitting and soon can be adjusted only with difficulty. In addition to the above, some wrenches have been provided with locking means which will shift between locking and unlocking position as a result of the wrench being used and jarred during such use. For example, it is a not too uncommon practice for the user of such a wrench to utilize the wrench somewhat as a hammer in order to strike an object upon which work is being performed a sharp blow. When the wrench is so used, the locking means will spring out of locking position into unlocking position with the result that. the jaws will shift through further use. Our invention is designed to eliminate these disadvantages.

It is a general object of our invention to provide a novel and improved adjustable wrench having improved locking means of simple and inexpensive construction and operation and also having lock retaining means to preclude the locking mechanism from shifting to unlocked position during use of the wrench.

A more specific object is to provide a novel and improved adjustable wrench having improved locking means simple and inexpensive to manufacture and assemble, which can be operated easily, and which has inherent resilient mechanism for retaining the locking means in locked position as desired.

Another object is to provide a novel and improved adjustable wrench constructed so as to make it permissible to utilize the same in any desired manner without causing the locking means to shift to unlocked position.

Another object is to provide a novel and improved adjustable wrench having locking means which is positively and resiliently held in locking position so as to prevent the locking mechanism from shifting to unlocked position during the use of the wrench.

These and other objects and advantages of our invention will more fully appear from the following description, made in connection with the accompanying drawings, wherein like reference characters refer to the same or similar parts throughout the several views and in which:

Fig. 1 is a fragmentary elevational view of a wrench embodying our invention; A

Fig. 2 is a fragmentary elevational view of the same wrench with parts broken away to better illustrate the novel features thereof;

Fig. 3 is a sectional view taken along. lines 3-3 of Fig. 1;

Fig. 4 is a perspective view of the shiftable platememher which carries the worm-locking element; and

Fig. 5 is a perspective view of the spring and mushroom shaped pin which serve to lock the shiftable plate member which carries the worm-locking element against shifting movement.

The embodiment of our invention shown in Figs. 1-5 includes a handle member 10 provided with a head 11 having an integral jaw 12, the top of the head being formed with a guide channel 13 of generally inverted T-shape in transverse cross-section and being also formed with a rectangular opening 14 which intersects the head of the T of the guide channel 13. Slidably mountedin the guide channel 13 is. a movable second jaw member 15 having an inverted T-portion 16, the head of the T being provided with a rack 17. Mounted within the rectangular opening 14 in the head is a worm 13 in mesh vwith the teeth of the rack 17, the. worm being supported on a shaft or pin 19 which is threaded at its inner end into the head 11 of the wrench. This shaft 19 is cylindrical in shape and of uniform diameter throughout its length. All of these parts as hereinbefore described are conventional in open end wrenches and are merely illustrative of the type of wrench in which the invention may be applied. The worm 18 is of somewhat different construction as will be hereinafter described.

It will be noted that the worm 18 is rotatably mounted in a fairly close fit upon the cylindrical pin or shaft 19. This. is important for it insures that upon slight wear there will not be sufficient play to cause the wrench to be worked with difficulty. One end portion of the worm 18 is provided with an annularly arranged rack 20 which is arranged so that its axis is the axis of the shaft 19.

Mounted on the shaft 19 is a plate member 21. This plate member 21 is positioned between the end portion of the worm 18 which carries the rack 20, and the fixed jaw 12. One side of the plate member 21 adjacent its peripheral portion carries a locking element or dog 22 which is adapted to fit into the recesses in the rack 20 to preclude rotation of the worm 18 about the shaft 19 when desired. The plate member 21 has an opening 21a which is elongated in the direction transversely of the head 11 so that the plate member 21 may be shifted radially of the shaft 19 and transversely of the head 11 to cause the locking element or dog 22 to engage and disengage the rack 20 of the worm 18. At opposite sides of the plate member 21 there is one of a pair of ears 23 and 24 which extend normal to the plane of the plate member 21 and parallel to the exterior side surface of the head 11. Each side surface of the head 11 is provided with one of a pair of recesses 25 and 26 which are shaped to conform to the ears 23 and 24 and are positioned to receive these cars therein when the plate Y member 21 is shifted to cause the locking element or dog 22 to shift between worm-locking and unlocking position.

As best shown in Fig. 4, the plate member 21 has a pair of spaced apertures 21b and 210 formed therethrough adjacent the opening 21a. These apertures 21b and 210, or recesses as they may be considered, are spaced transversely of the head 11 and of the axis of rotation of the shaft 19 and, of course, they shift transversely of the head 11 as the plate member 21 is shifted by pressure upon the ears 23 or 24.

As best shown in Fig. 2, the recesses 21b and 210 are so constructed and arranged as to be disposed opposite the retaining mechanism for the plate 21. As shown in- Fig. 2, the head 11 has a'relatively small bore 11a formed therein immediately adjacent the threaded bore which receives the shaft 19. This bore communicates with the rectangular opening 14 and carries therein a small coiled spring 27 within which is mounted a mushroom shaped pin 28. The head 28a of the mushroom shaped pin bears against the plate member21 and is constantly urged outwardly by the spring 27. The head 28a of the pin 28 slips into the recesses 21b or 210, depending upon the position to which the plate member is moved.

When the wrench is assembled as shown in Figs. 1-3, the plate 21 is free to move relative to the shaft 19 through the application of pressure to either of the ears 23 or 24. When the pressure is exerted upon the car 23, the plate member 21 moves radially of the shaft 19 and the lock element 22 slips into one of the recesses or openings betweenthe teeth of the rack 20 which is formed on the adjacent end of the worm 18. This serves to effectively lock the worm 18 against additional rotary movement and thereby locks the movable jaw 15 against shifting movement within the channel 13. It will be noted that the ear 23 is disposed adjacent the end of the shaft 19 and worm 18 which are nearest the fixed jaw member 12. The ear 23 is so located as to make it most convenient for the user in locking the worm 18 while using the wrench.

When pressure is applied to the ear 23, the head 28a of the pin 28 is forced inwardly by the shifting action of the plate 21 and is caused to leave the recess 21c and slip into the recess 21b. In so doing, the plate 21 is positively held against any shifting action even though the wrench may be improperly used as a hammer or the like, for despite repeated pounding of an object with the head of the wrench, the mushroom shaped pin 28 will prevent the plate member 21 from shifting radially of the shaft 19 and thereby will preclude the worm 18 from rotating and permitting the movable jaw 15 to shift. The spring 27 constantly urges the pin 28 into one of the recesses 21b or 210 depending upon the position of the plate member 21 relative to the shaft 19. When pressure is applied to the ear 24 the locking element 22 shifts outwardly with the plate 21 and out of locking portions of the parts without departing from the scope of our invention which consists of the matter shown and described herein and set forth in the appended claims.

relation with the rack 20 carried at the end of the worm 18. 7

From the above it can be readily seen that we have provided a locking adjustable open end wrench which has inherent means for positively preventing the locking mechanism from shifting out of locking engagement with the worm 18. The cooperative action between the mushroom shaped pin 28, the coiled spring 27 and the recesses 21b and 21c positively prevent the plate member 21, which. carries the lock element 22, from shifting out of the position to which it has been moved by the user, for no amount of jarring or pounding will cause the plate member 21 to shift out of the position in which it is. being held by the lock retaining mechanism comprised of the spring 27, the pin 28 and the recesses 21b and 210.

It will also be readily seen that our improved wrench is extremely simple in construction and highly eifective in operation. The cost of assembly is not appreciably increased while the advantages attained make the wrench substantially more desirable and efficient for use.

It will be noted that the bore 11a is not quite parallel to the threaded bore into which the shaft 19 is threaded. This is true because the bore 11a must be formed by passing the bore-forming tool through the opening provided to accommodate the outer end of the shaft 19. We have found, however, that the slight angulation between the axis of the bore 11a and that of the openings which receive the shaft 15, is not sufiicient to hinder the operation or efi'iciency of the lock retaining mechanism which includes the spring 27 and the mushroom shaped pin 28.

It will, of course, be understood that various changes may be made in the form, details, arrangement and pro- What is claimed is:

1. A wrench comprising a head provided with a fixed jaw, a second jaw movable in said head and having a rack thereon, a worm rotatably mounted in said head in driving engagement with said rack, movable positive-action worm-locking means carried by said head in position to engage one end of said worm, said means being movable radially of said worm between worm-locking and unlocking positions as desired, and resilient retaining means carried by said head in worm-locking-means-engagii1g relation, whereby said worm-locking means will be positively prevented during use from being jarred from worm-locking position after having been moved to said position for such use.

2. A wrench comprising a head provided with a fixed jaw, a second jaw member movable in said head and having a rack thereon, a worm rotatably mounted in said head in driving engagement with said rack, and resiliently retained positive-action jaw-locking means carried by said head and movable radially of said worm within the confines of said head between jaw locking and unlocking positions and to positively prevent said movable jaw from becoming unlocked during use as a result of jarring of the wrench and the like after having been locked by said jaw locking means.

3. A wrench comprising a head provided with a fixed jaw, a second jaw movable in said head and having a rack thereon, a worm rotatably mounted in said head in driving engagement with said rack, shiftable positive-action worm-locking means carried by said head in position to engage one end only of said worm, said means being shiftable between worm-locking and unlocking positions in a direction transversely of the axis of rotation of said worm and of the general plane of said head, and resilient retaining means carried by said head in worm-lockingmeans-engaging relation, whereby said worm-locking means will be positively prevented from being jarred from worm-locking position during use after having been moved to said position for such use.

4. A wrench comprising a head provided with a fixed jaw, a second jaw movable in said head and having a rack thereon, a worm rotatably mounted in said head in driving engagement with said rack, locking-engaging means carried by said worm, a shaft mounted in said head and carrying said worm for rotation thereon, a plate member mounted on said shaft and having an opening through which said shaft extends, said plate member being shiftable radially of said shaft, a lock element carried by said plate member and shiftable therewith radially of said shaft into and out of locking engagement with said lock-engaging means on said worm, whereby the rotational movement of said worm may be prevented as desired, and resilient retaining means carried by said head in lock-element-retaining relation, whereby said lock element will be positively prevented during use from being jarred from locking position after having been moved to said position for such use.

5. The structure defined in claim 4 wherein said plate member is provided with a pair of recesses spaced transversely of the plane of said head and of the axis of rotation of said worm and disposed opposite said retaining means, said recesses being positioned and arranged so that said retaining means may slip into one of said recesses at each of said positions of said lock element.

6. The structure defined in claim 4 wherein said head has a bore adjacent said plate member and said retaining means includes a coiled spring mounted in said bore and a retaining pin mounted upon said spring and bearing against said plate member to positively prevent said plate member from being shifted by jarring and the like during use of the wrench. 1

7. A wrench comprising a head provided with a fixed jaw, a second jaw movable in said head and having a rack formed therein, a shaft mounted in said head adjacent said jaw, a worm rotatably mounted on said shaft in said head in driving engagement with said rack, a second rack mounted on one end portion of said worm in annular arrangement around said shaft, a plate member mounted on said shaft and having an opening through which said shaft extends and being shiftable radially of said'shaft, a lock element carried by said plate member and being shiftable therewith radially of said shaft into and out of locking engagement with said worm rack whereby the rotational movement of said worm may be prevented, an ear member extending laterally of said plate member at one edge thereof and extending generally parallel to the general plane of said head, said ear memher being movable inwardly toward said head to carry said lock element into locking engagement with said worm rack, said ear member being disposed adjacent the end of said worm nearest said fixed jaw, and resilient retaining means carried by said head and engaging said plate member, whereby said plate member will be positively prevented during use of the wrench from being shifted by jarring and the'like to carry said lock element out of locking engagement with said worm rack after having been moved to such position for such use.

References Cited in the file of this patent UNITED STATES PATENTS 785,953 Jarnberg Mar. 28 ,1905 1,148,410 Smith et al July 27, 1915 1,414,839 Stuarts May 2, 1922 1,729,640 Vallone Oct. 1, 1929 1,846,380 Anderson Feb. 23, 1932 1,912,597 Schuerlin June 6, 1933 2,316,455 Richardson Apr. 13, 1943 FOREIGN PATENTS 47,960 Sweden Nov. 24, 1920 72,035 Denmark Jan. 15, 1951 UNITED STATES PATENT OFFICE CERTIFICATE OF- CORRECTION Patent No. 2,849,908 September 2, 1958 J 01111 E, Swanstrom et a1,

It is hereby certified that error appears i'n the printed specification of The above numbered patent requiring correction and that the said Letters Patent should read as corrected below.

Column 4, line 46, for "locking-=engaging" read look engaging b .Signed and sealed this 25th day of November 1958 (SEAL) Attest:

KARL H- AXLINE Attesting Oficer ROBERT C. WATSON Commissioner of Patents 

